This series add a virtual thermal sensor.
It could be used to get a temperature using some thermal sensors.
Currently, the supported operations are max, min and avg.
The virtual sensor could be easily extended to support others operations.
Changes in v2:
- Fix some warnings / errors reported by kernel test robot
- rename some struct and functions with a more accurate name
- update the dt bindings: rename type attribute to aggregation-function
- factorize a little bit the aggregation functions
Changes in v3:
- Aggregate thermal zone instead of thermal sensors
- Use try_get_module / put_module to prevent thermal providers to be removed
- Update the bindings, to be more accurate
Changes in v4:
- Fix two warnings reported by kernel test robot
Alexandre Bailon (2):
dt-bindings: Add DT bindings for the DT-based virtual sensor driver
thermal: add a virtual sensor to aggregate temperatures
Alexandre Bailon (2):
dt-bindings: Add DT bindings for the DT-based virtual sensor driver
thermal: add a virtual sensor to aggregate temperatures
.../thermal/virtual,thermal-sensor.yaml | 86 +++++++
drivers/thermal/Kconfig | 8 +
drivers/thermal/Makefile | 1 +
drivers/thermal/virtual_thermal_sensor.c | 218 ++++++++++++++++++
include/dt-bindings/thermal/virtual-sensor.h | 15 ++
5 files changed, 328 insertions(+)
create mode 100644 Documentation/devicetree/bindings/thermal/virtual,thermal-sensor.yaml
create mode 100644 drivers/thermal/virtual_thermal_sensor.c
create mode 100644 include/dt-bindings/thermal/virtual-sensor.h
--
2.25.1
This adds the DT bindings for the DT-based virtual sensor driver.
This driver provides a way, using DT, to aggregate the temperature
of multiple thermal zones and get some useful data from it.
Signed-off-by: Alexandre Bailon <[email protected]>
---
.../thermal/virtual,thermal-sensor.yaml | 86 +++++++++++++++++++
include/dt-bindings/thermal/virtual-sensor.h | 15 ++++
2 files changed, 101 insertions(+)
create mode 100644 Documentation/devicetree/bindings/thermal/virtual,thermal-sensor.yaml
create mode 100644 include/dt-bindings/thermal/virtual-sensor.h
diff --git a/Documentation/devicetree/bindings/thermal/virtual,thermal-sensor.yaml b/Documentation/devicetree/bindings/thermal/virtual,thermal-sensor.yaml
new file mode 100644
index 000000000000..b404fd4b2b38
--- /dev/null
+++ b/Documentation/devicetree/bindings/thermal/virtual,thermal-sensor.yaml
@@ -0,0 +1,86 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+# Copyright 2021 BayLibre
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/thermal/virtual,thermal-sensor.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Virtual thermal sensor binding
+
+maintainers:
+ - Alexandre Bailon <[email protected]>
+
+description: |
+ The virtual thermal sensor device provides a way to aggregate the temperature
+ from multiple thermal zones. Basically, this could be used to get the
+ maximum, minimum or average temperature.
+
+allOf:
+ - $ref: thermal-sensor.yaml#
+
+properties:
+ compatible:
+ const: virtual,thermal-sensor
+
+ aggregation-function:
+ $ref: /schemas/types.yaml#/definitions/uint32
+ description:
+ Used to select the operations to perform on the sensors to get the virtual
+ sensor temperature.
+ enum:
+ - VIRTUAL_THERMAL_SENSOR_MIN_VAL
+ - VIRTUAL_THERMAL_SENSOR_MAX_VAL
+ - VIRTUAL_THERMAL_SENSOR_AVG_VAL
+
+ thermal-sensors:
+ $ref: /schemas/types.yaml#/definitions/string-array
+ description:
+ The names of the thermal zone to aggregate.
+
+required:
+ - aggregation-function
+ - thermal-sensors
+
+additionalProperties: true
+
+examples:
+ - |
+ #include <dt-bindings/thermal/thermal.h>
+ #include <dt-bindings/thermal/virtual-sensor.h>
+ #include <dt-bindings/interrupt-controller/arm-gic.h>
+ #include <dt-bindings/clock/mt8192-clk.h>
+
+ lvts: lvts@1100b000 {
+ compatible = "mediatek,mt6873-lvts";
+ reg = <0x1100b000 0x1000>;
+ clocks = <&infracfg CLK_INFRA_THERM>;
+ clock-names = "lvts_clk";
+ #thermal-sensor-cells = <1>;
+ interrupts = <GIC_SPI 147 IRQ_TYPE_LEVEL_HIGH>;
+ };
+
+ cpu_max_sensor: cpu_max_sensor {
+ compatible = "virtual,thermal-sensor";
+ #thermal-sensor-cells = <1>;
+ aggregation-function = <VIRTUAL_THERMAL_SENSOR_MAX_VAL>;
+ thermal-sensors = "cpu1", "cpu2";
+ };
+
+ thermal_zones: thermal-zones {
+ cpu1 {
+ polling-delay = <0>; /* milliseconds */
+ polling-delay-passive = <0>; /* milliseconds */
+ thermal-sensors = <&lvts 0>;
+ };
+ cpu2 {
+ polling-delay = <0>; /* milliseconds */
+ polling-delay-passive = <0>; /* milliseconds */
+ thermal-sensors = <&lvts 1>;
+ };
+ cpu_max {
+ polling-delay = <0>; /* milliseconds */
+ polling-delay-passive = <0>; /* milliseconds */
+ thermal-sensors = <&cpu_max_sensor 0>;
+ };
+ };
+...
diff --git a/include/dt-bindings/thermal/virtual-sensor.h b/include/dt-bindings/thermal/virtual-sensor.h
new file mode 100644
index 000000000000..6254b2aa8f5c
--- /dev/null
+++ b/include/dt-bindings/thermal/virtual-sensor.h
@@ -0,0 +1,15 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * This header provides constants for virtual thermal sensor bindings.
+ *
+ * Copyright (C) 2021 BayLibre
+ */
+
+#ifndef _DT_BINDINGS_THERMAL_VIRTUAL_SENSOR_H
+#define _DT_BINDINGS_THERMAL_VIRTUAL_SENSOR_H
+
+#define VIRTUAL_THERMAL_SENSOR_MIN_VAL 0
+#define VIRTUAL_THERMAL_SENSOR_MAX_VAL 1
+#define VIRTUAL_THERMAL_SENSOR_AVG_VAL 2
+
+#endif /* _DT_BINDINGS_THERMAL_VIRTUAL_SENSOR_H */
--
2.25.1
This adds a virtual thermal sensor driver that reads temperature from
multiple hardware sensors and returns an aggregated temperature.
Currently, this supports three aggregations:
the minimum, maximum and average temperature.
Signed-off-by: Alexandre Bailon <[email protected]>
---
drivers/thermal/Kconfig | 8 +
drivers/thermal/Makefile | 1 +
drivers/thermal/virtual_thermal_sensor.c | 218 +++++++++++++++++++++++
3 files changed, 227 insertions(+)
create mode 100644 drivers/thermal/virtual_thermal_sensor.c
diff --git a/drivers/thermal/Kconfig b/drivers/thermal/Kconfig
index d7f44deab5b1..b326fae5ad1d 100644
--- a/drivers/thermal/Kconfig
+++ b/drivers/thermal/Kconfig
@@ -228,6 +228,14 @@ config THERMAL_MMIO
register or shared memory, is a potential candidate to work with this
driver.
+config VIRTUAL_THERMAL
+ tristate "DT-based virtual thermal sensor driver"
+ depends on THERMAL_OF || COMPILE_TEST
+ help
+ This option enables the generic DT-based thermal sensor aggregator.
+ This driver creates a thermal sensor that reads multiple hardware
+ sensors and aggregates their output.
+
config HISI_THERMAL
tristate "Hisilicon thermal driver"
depends on ARCH_HISI || COMPILE_TEST
diff --git a/drivers/thermal/Makefile b/drivers/thermal/Makefile
index 82fc3e616e54..8bf55973059c 100644
--- a/drivers/thermal/Makefile
+++ b/drivers/thermal/Makefile
@@ -60,3 +60,4 @@ obj-$(CONFIG_UNIPHIER_THERMAL) += uniphier_thermal.o
obj-$(CONFIG_AMLOGIC_THERMAL) += amlogic_thermal.o
obj-$(CONFIG_SPRD_THERMAL) += sprd_thermal.o
obj-$(CONFIG_KHADAS_MCU_FAN_THERMAL) += khadas_mcu_fan.o
+obj-$(CONFIG_VIRTUAL_THERMAL) += virtual_thermal_sensor.o
diff --git a/drivers/thermal/virtual_thermal_sensor.c b/drivers/thermal/virtual_thermal_sensor.c
new file mode 100644
index 000000000000..9f38af925fd1
--- /dev/null
+++ b/drivers/thermal/virtual_thermal_sensor.c
@@ -0,0 +1,218 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * virtual_thermal_sensor.c - DT-based virtual thermal sensor driver.
+ *
+ * Copyright (c) 2021 BayLibre
+ */
+
+#include <linux/err.h>
+#include <linux/export.h>
+#include <linux/module.h>
+#include <linux/of_device.h>
+#include <linux/of_platform.h>
+#include <linux/slab.h>
+#include <linux/thermal.h>
+#include <linux/types.h>
+#include <linux/string.h>
+
+#include <dt-bindings/thermal/virtual-sensor.h>
+
+struct virtual_thermal_zone_device {
+ struct thermal_zone_device *zone;
+ struct module *owner;
+};
+
+struct virtual_thermal_sensor {
+ int count;
+ struct virtual_thermal_zone_device *zones;
+ struct thermal_zone_device *tzd;
+ int (*aggr_temp)(int temp1, int temp2);
+
+ struct list_head node;
+};
+
+static int max_temp(int temp1, int temp2)
+{
+ return max(temp1, temp2);
+}
+
+static int min_temp(int temp1, int temp2)
+{
+ return min(temp1, temp2);
+}
+
+static int avg_temp(int temp1, int temp2)
+{
+ return (temp1 + temp2) / 2;
+}
+
+static int virtual_thermal_sensor_get_temp(void *data, int *temperature)
+{
+ struct virtual_thermal_sensor *sensor = data;
+ int max_temp = INT_MIN;
+ int temp;
+ int i;
+
+ for (i = 0; i < sensor->count; i++) {
+ struct thermal_zone_device *zone;
+
+ zone = sensor->zones[i].zone;
+ zone->ops->get_temp(zone, &temp);
+ max_temp = sensor->aggr_temp(max_temp, temp);
+ }
+
+ *temperature = max_temp;
+
+ return 0;
+}
+
+static const struct thermal_zone_of_device_ops virtual_thermal_sensor_ops = {
+ .get_temp = virtual_thermal_sensor_get_temp,
+};
+
+static int virtual_thermal_sensor_get_module(struct virtual_thermal_zone_device *zone,
+ const char *name)
+{
+ struct platform_device *sensor_pdev;
+ struct device_node *node;
+
+ node = of_find_node_by_name(NULL, name);
+ if (!node)
+ return -ENODEV;
+
+ node = of_parse_phandle(node, "thermal-sensors", 0);
+ if (!node)
+ return -ENODEV;
+
+ sensor_pdev = of_find_device_by_node(node);
+ if (!sensor_pdev)
+ return -ENODEV;
+
+ if (!sensor_pdev->dev.driver)
+ return -EPROBE_DEFER;
+
+ if (!try_module_get(sensor_pdev->dev.driver->owner))
+ return -ENODEV;
+
+ zone->owner = sensor_pdev->dev.driver->owner;
+
+ return 0;
+}
+
+static void virtual_thermal_sensor_put_modules(struct virtual_thermal_sensor *sensor)
+{
+ int i;
+
+ for (i = 0; i < sensor->count; i++) {
+ if (sensor->zones[i].zone)
+ module_put(sensor->zones[i].owner);
+ }
+}
+
+static int virtual_thermal_sensor_probe(struct platform_device *pdev)
+{
+ struct virtual_thermal_sensor *sensor;
+ struct device *dev = &pdev->dev;
+ struct property *prop;
+ const char *name;
+ u32 type;
+ int ret;
+ int i = 0;
+
+ sensor = devm_kzalloc(dev, sizeof(*sensor), GFP_KERNEL);
+ if (!sensor)
+ return -ENOMEM;
+ sensor->count = of_property_count_strings(dev->of_node, "thermal-sensors");
+ if (sensor->count <= 0)
+ return -EINVAL;
+
+ sensor->zones = devm_kmalloc_array(dev, sensor->count,
+ sizeof(*sensor->zones),
+ GFP_KERNEL);
+ if (!sensor->zones)
+ return -ENOMEM;
+
+ of_property_for_each_string(dev->of_node, "thermal-sensors", prop, name) {
+ struct virtual_thermal_zone_device *virtual_zone;
+ struct thermal_zone_device *zone;
+
+ virtual_zone = &sensor->zones[i++];
+
+ zone = thermal_zone_get_zone_by_name(name);
+ if (IS_ERR(zone))
+ return PTR_ERR(zone);
+
+ ret = virtual_thermal_sensor_get_module(virtual_zone, name);
+ if (ret)
+ goto err;
+
+ virtual_zone->zone = zone;
+ }
+
+ ret = of_property_read_u32(dev->of_node, "aggregation-function", &type);
+ if (ret)
+ return ret;
+
+ switch (type) {
+ case VIRTUAL_THERMAL_SENSOR_MAX_VAL:
+ sensor->aggr_temp = max_temp;
+ break;
+ case VIRTUAL_THERMAL_SENSOR_MIN_VAL:
+ sensor->aggr_temp = min_temp;
+ break;
+ case VIRTUAL_THERMAL_SENSOR_AVG_VAL:
+ sensor->aggr_temp = avg_temp;
+ break;
+ default:
+ return -EINVAL;
+ }
+
+ sensor->tzd = devm_thermal_zone_of_sensor_register(dev, 0, sensor,
+ &virtual_thermal_sensor_ops);
+ if (IS_ERR(sensor->tzd))
+ return PTR_ERR(sensor->tzd);
+
+ platform_set_drvdata(pdev, sensor);
+
+ return 0;
+
+err:
+ virtual_thermal_sensor_put_modules(sensor);
+
+ return ret;
+}
+
+static int virtual_thermal_sensor_remove(struct platform_device *pdev)
+{
+ struct virtual_thermal_sensor *sensor;
+
+ sensor = platform_get_drvdata(pdev);
+ list_del(&sensor->node);
+
+ virtual_thermal_sensor_put_modules(sensor);
+
+ return 0;
+}
+
+static const struct of_device_id virtual_thermal_sensor_of_match[] = {
+ {
+ .compatible = "virtual,thermal-sensor",
+ },
+ {
+ },
+};
+MODULE_DEVICE_TABLE(of, virtual_thermal_sensor_of_match);
+
+static struct platform_driver virtual_thermal_sensor = {
+ .probe = virtual_thermal_sensor_probe,
+ .remove = virtual_thermal_sensor_remove,
+ .driver = {
+ .name = "virtual-thermal-sensor",
+ .of_match_table = virtual_thermal_sensor_of_match,
+ },
+};
+
+module_platform_driver(virtual_thermal_sensor);
+MODULE_AUTHOR("Alexandre Bailon <[email protected]>");
+MODULE_DESCRIPTION("Virtual thermal sensor");
+MODULE_LICENSE("GPL v2");
--
2.25.1
Daniel, Amit,
Alexandre Bailon <[email protected]> writes:
> This series add a virtual thermal sensor.
> It could be used to get a temperature using some thermal sensors.
> Currently, the supported operations are max, min and avg.
> The virtual sensor could be easily extended to support others operations.
>
> Changes in v2:
> - Fix some warnings / errors reported by kernel test robot
> - rename some struct and functions with a more accurate name
> - update the dt bindings: rename type attribute to aggregation-function
> - factorize a little bit the aggregation functions
> Changes in v3:
> - Aggregate thermal zone instead of thermal sensors
> - Use try_get_module / put_module to prevent thermal providers to be removed
> - Update the bindings, to be more accurate
> Changes in v4:
> - Fix two warnings reported by kernel test robot
Any more feedback on this series?
Thanks,
Kevin
On Mon, Jan 24, 2022 at 5:58 PM Kevin Hilman <[email protected]> wrote:
>
> Daniel, Amit,
>
> Alexandre Bailon <[email protected]> writes:
>
> > This series add a virtual thermal sensor.
> > It could be used to get a temperature using some thermal sensors.
> > Currently, the supported operations are max, min and avg.
> > The virtual sensor could be easily extended to support others operations.
> >
> > Changes in v2:
> > - Fix some warnings / errors reported by kernel test robot
> > - rename some struct and functions with a more accurate name
> > - update the dt bindings: rename type attribute to aggregation-function
> > - factorize a little bit the aggregation functions
> > Changes in v3:
> > - Aggregate thermal zone instead of thermal sensors
> > - Use try_get_module / put_module to prevent thermal providers to be removed
> > - Update the bindings, to be more accurate
> > Changes in v4:
> > - Fix two warnings reported by kernel test robot
>
> Any more feedback on this series?
Hopefully, I'll get to it this week and I'll let you know.
"Rafael J. Wysocki" <[email protected]> writes:
> On Mon, Jan 24, 2022 at 5:58 PM Kevin Hilman <[email protected]> wrote:
>>
>> Daniel, Amit,
>>
>> Alexandre Bailon <[email protected]> writes:
>>
>> > This series add a virtual thermal sensor.
>> > It could be used to get a temperature using some thermal sensors.
>> > Currently, the supported operations are max, min and avg.
>> > The virtual sensor could be easily extended to support others operations.
>> >
>> > Changes in v2:
>> > - Fix some warnings / errors reported by kernel test robot
>> > - rename some struct and functions with a more accurate name
>> > - update the dt bindings: rename type attribute to aggregation-function
>> > - factorize a little bit the aggregation functions
>> > Changes in v3:
>> > - Aggregate thermal zone instead of thermal sensors
>> > - Use try_get_module / put_module to prevent thermal providers to be removed
>> > - Update the bindings, to be more accurate
>> > Changes in v4:
>> > - Fix two warnings reported by kernel test robot
>>
>> Any more feedback on this series?
>
> Hopefully, I'll get to it this week and I'll let you know.
Thanks Rafael,
Kevin
On Mon, Jan 24, 2022 at 10:23 PM Kevin Hilman <[email protected]> wrote:
>
> "Rafael J. Wysocki" <[email protected]> writes:
>
> > On Mon, Jan 24, 2022 at 5:58 PM Kevin Hilman <[email protected]> wrote:
> >>
> >> Daniel, Amit,
> >>
> >> Alexandre Bailon <[email protected]> writes:
> >>
> >> > This series add a virtual thermal sensor.
> >> > It could be used to get a temperature using some thermal sensors.
> >> > Currently, the supported operations are max, min and avg.
> >> > The virtual sensor could be easily extended to support others operations.
> >> >
> >> > Changes in v2:
> >> > - Fix some warnings / errors reported by kernel test robot
> >> > - rename some struct and functions with a more accurate name
> >> > - update the dt bindings: rename type attribute to aggregation-function
> >> > - factorize a little bit the aggregation functions
> >> > Changes in v3:
> >> > - Aggregate thermal zone instead of thermal sensors
> >> > - Use try_get_module / put_module to prevent thermal providers to be removed
> >> > - Update the bindings, to be more accurate
> >> > Changes in v4:
> >> > - Fix two warnings reported by kernel test robot
> >>
> >> Any more feedback on this series?
> >
> > Hopefully, I'll get to it this week and I'll let you know.
>
> Thanks Rafael,
Done, please see
https://lore.kernel.org/linux-pm/CAJZ5v0jejFG76OfewYg3kmKv4xwLdRBpC+zRpJ9Jom+tqo7qyg@mail.gmail.com/
"Rafael J. Wysocki" <[email protected]> writes:
> On Mon, Jan 24, 2022 at 10:23 PM Kevin Hilman <[email protected]> wrote:
>>
>> "Rafael J. Wysocki" <[email protected]> writes:
>>
>> > On Mon, Jan 24, 2022 at 5:58 PM Kevin Hilman <[email protected]> wrote:
>> >>
>> >> Daniel, Amit,
>> >>
>> >> Alexandre Bailon <[email protected]> writes:
>> >>
>> >> > This series add a virtual thermal sensor.
>> >> > It could be used to get a temperature using some thermal sensors.
>> >> > Currently, the supported operations are max, min and avg.
>> >> > The virtual sensor could be easily extended to support others operations.
>> >> >
>> >> > Changes in v2:
>> >> > - Fix some warnings / errors reported by kernel test robot
>> >> > - rename some struct and functions with a more accurate name
>> >> > - update the dt bindings: rename type attribute to aggregation-function
>> >> > - factorize a little bit the aggregation functions
>> >> > Changes in v3:
>> >> > - Aggregate thermal zone instead of thermal sensors
>> >> > - Use try_get_module / put_module to prevent thermal providers to be removed
>> >> > - Update the bindings, to be more accurate
>> >> > Changes in v4:
>> >> > - Fix two warnings reported by kernel test robot
>> >>
>> >> Any more feedback on this series?
>> >
>> > Hopefully, I'll get to it this week and I'll let you know.
>>
>> Thanks Rafael,
>
> Done, please see
> https://lore.kernel.org/linux-pm/CAJZ5v0jejFG76OfewYg3kmKv4xwLdRBpC+zRpJ9Jom+tqo7qyg@mail.gmail.com/
Thank you.
On 11/01/2022 11:33, Alexandre Bailon wrote:
> This adds the DT bindings for the DT-based virtual sensor driver.
> This driver provides a way, using DT, to aggregate the temperature
> of multiple thermal zones and get some useful data from it.
>
> Signed-off-by: Alexandre Bailon <[email protected]>
> ---
[ ... ]
> +description: |
> + The virtual thermal sensor device provides a way to aggregate the temperature
> + from multiple thermal zones. Basically, this could be used to get the
> + maximum, minimum or average temperature.
> +
> +allOf:
> + - $ref: thermal-sensor.yaml#
> +
> +properties:
> + compatible:
> + const: virtual,thermal-sensor
> +
> + aggregation-function:
> + $ref: /schemas/types.yaml#/definitions/uint32
> + description:
> + Used to select the operations to perform on the sensors to get the virtual
> + sensor temperature.
> + enum:
> + - VIRTUAL_THERMAL_SENSOR_MIN_VAL
> + - VIRTUAL_THERMAL_SENSOR_MAX_VAL
> + - VIRTUAL_THERMAL_SENSOR_AVG_VAL
> +
> + thermal-sensors:
> + $ref: /schemas/types.yaml#/definitions/string-array
> + description:
> + The names of the thermal zone to aggregate.
IMO this is not correct. We are dealing with virtual sensor in order to
aggregate a group of sensors in a thermal zone. But actually this
description aggregates the thermal zones.
I recalled a detail about the binding from the old 'txt' format from [1].
"- thermal-sensors: A list of thermal sensor phandles and sensor specifier
Type: list of phandles + sensor specifier used while monitoring the
thermal zone."
This information was lost in the conversion to yaml with commit
1202a442a31fd
In addition, the "coefficients" property tells the 'thermal-sensors'
property can have multiple sensors.
So actually, the bindings should be fixed as part of the information was
lost during of the txt -> yaml conversion.
And the multiple sensors per thermal zone could be implemented as that
was something planned since a while.
I realize we initially asked to create a virtual sensor but that is not
the most adequate ATM. Doing the multiple sensors support makes more
sense to me, especially it does not require any extra binding except an
attribute tell what kind of temperature aggregation we do. Defaulting to
max should suffice when no aggregation method is set.
-- Daniel
[1]
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/Documentation/devicetree/bindings/thermal/thermal.txt?h=v4.5#n147
--
<http://www.linaro.org/> Linaro.org │ Open source software for ARM SoCs
Follow Linaro: <http://www.facebook.com/pages/Linaro> Facebook |
<http://twitter.com/#!/linaroorg> Twitter |
<http://www.linaro.org/linaro-blog/> Blog